1. Field of the Invention
The present invention relates to a valve arrangement of the kind that includes a valve housing which has an inlet port and two outlet ports for fluid flowing through the housing. The valve housing includes a first valve chamber which accommodates a valve element that can move between two end positions and that has two surfaces which each co-act with a respective outlet port and which function to close an associated outlet port in respective first and second end positions of the valve elements. The valve arrangement further including means for switching the valve element between the positions and the valve element being mounted on one end of a pivotal arm.
2. Related Art
Valve arrangements of this kind are known, for instance, from EP 0 492 242.
The object of the present invention is to provide a novel and improved valve arrangement chat comprises removable parts, and which can be reset quickly and positively and which will not become adjusted to a neutral position in which both of said output ports communicate permanently with the inlet port at one and the same time.
It is proposed to this end in accordance with the invention that the valve element of a valve arrangement of the aforedescribed kind shall be given the form of a valve plate or valve disc that has mutually opposite a valve element surfaces disposed for alternate co-action with a respective outlet port; and in that the arm carrying said valve element is coupled mechanically to a further valve element accommodated in a separate, second valve chamber such as to drive said further valve element between two positions in which said element connects one or the other of two fluid inlet ports to a fluid outlet port which is common to said two fluid inlet ports. This arrangement provides an improved valve arrangement with the aid of simple means.
Further characteristic features of the invention will be apparent from the following wherein an object of the invention is to provide that the pivotal arm extends into the further valve space and carries the further valve element at a second end located within the further valve space, wherewith the further valve element also has the form of a valve plate which includes mutually opposite valve-element surfaces for co-action with a respective associated inlet port.
Another object of the invention is to provide that the valve arrangement is co-ordinated with a double-acting pump which includes two spaces having valve-controlled respective inlets and outlets for a gaseous drive fluid and a liquid working fluid transported by the pump, wherewith the spaces are divided into an operating chamber and a working chamber by means of a movable partition wall in the form of a diaphragm, in that a device for transferring movement of one partition wall to the other partition wall, and vice versa, extends between the movable partition walls, and in that each of the operating-chamber inlets is coupled to its respective outlet port associated with the first valve space of the valve arrangement, and each operating chamber outlet is connected to its respective fluid inlet port associated with the second valve space.
A still further object of the invention is to provide that the each operating chamber is connected to its respective outlet port of the valve arrangement via a conduit which is adapted to be closed by the associated partition wall immediately prior to the commencement of a working stroke of the partition wall, and in that a fluid bleed passageway extends between the outlet ports and the inlet port common to the outlet ports.
Another object of the invention is to provide that each of the bleed passageways is comprised of a bore or channel that extends through the material of the valve housing or through associated valve element.
An object of the invention is to provide that the partition walls include bellow-like structures which are open to the conduits and which function to generate an over pressure in an associated conduit when closing the conduit.
A still further object of the invention is to provide that the operating chambers are located close together on both sides of the valve arrangement, and in that the partition walls are provided with pins which each extend into a respective outlet port and, when the partition walls are in their inner end positions, act on an associated valve-element surface so as to reset the valve element.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.